Wehrli 2001-2007 LB7/LLY/LBZ Duramax OEM Placement Coolant Tank Kit
Can I pick up my order or have it installed at your shop?
Can I pick up my order or have it installed at your shop?
Absolutely. We offer local pickup on most products and full professional installation at our shop in Washington, MO. Whether you just want to grab your parts or have our techs handle the install, we’ve got you covered. Give us a quick call at 636-429-7020 or message us to schedule a visit — we’ll make sure the parts are ready when you arrive.
How do I know if this part fits my vehicle?
How do I know if this part fits my vehicle?
Unsure if it’ll fit? No problem — that’s what we’re here for. Send us your vehicle’s year, make, and model, and we’ll verify fitment before you order. We can also point you toward compatible upgrades or supporting parts if needed.
What if I need to return a product or it’s defective?
What if I need to return a product or it’s defective?
Most unused items can be returned within 30 days in their original packaging. Some products are covered by a manufacturer’s warranty as well. If something arrives damaged or doesn’t meet your expectations, just let us know — we’ll help you get it replaced, refunded, or repaired. (Tracking updates are also emailed automatically once your order ships.)
What's the lead time on custom or fabricated parts?
What's the lead time on custom or fabricated parts?
Many of our parts are built to order — especially fabricated or performance components. These can take additional time to produce before shipping. Lead times vary by manufacturer and demand, but we’ll always keep you updated along the way. If you’re working on a tight schedule, reach out before ordering at 636-429-7020 and we’ll confirm current availability or estimated ship dates.
The plastic degas bottle on a 2001-2007 Chevrolet Silverado / GMC Sierra 2500HD/3500HD 6.6L Duramax LB7, LLY and LBZ yellows, stains and — more to the point — these trucks are known for coolant level sensor failures that mean replacing the tank anyway. The Wehrli OEM Placement Coolant Tank Kit (Manufacturer Part # WCF100645) replaces it with fabricated aluminum, a serviceable sensor and a sight glass.
Why Choose the Wehrli OEM Placement Coolant Tank Kit?
- Serviceable low coolant level sensor – this is the real argument. The factory sensor is moulded into the OEM tank and cannot be replaced on its own, so a failed sensor means a whole new reservoir. Wehrli's threads in and out.
- Billet aluminum sight glass, fitted before it ships – Wehrli installs and torques it after powder coat, because the thread is fine and easy to cross-thread. Nothing for you to fit.
- Fabricated aluminum – laser cut, CNC bent and TIG welded in house, in your choice of powder coat.
- Complete kit – billet anodized cap, overflow hose, sensor, sight glass and all mounting hardware.
- Factory mounting points – CAD designed for a precise fit using OEM mounting locations and OEM style hoses. No modifications.
- Finishes the engine bay – an OEM plastic tank sitting behind a fabricated aluminum air box is the thing that gives a build away.
Kit Includes
- Fabricated aluminum coolant tank with billet aluminum sight glass fitted
- Serviceable low coolant level sensor
- Black anodized CNC machined billet aluminum cap
- Overflow hose
- Installation hardware
Installation Highlights
Mounts in the OEM coolant tank location on the factory mounting points, basic hand tools. The cap is a two-prong design — line the prongs up with the grooves, push down and twist past the first detent until it locks.
Fitting the sensor: check the bung is clear of debris, coat the threads with a high temperature sealant such as Permatex, thread it in by hand and finish with a 13mm wrench. Then leave it at least 24 hours to cure before adding coolant — filling sooner is what causes a leak at the sensor.
Fits These Models
2001 through 2007 Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD with the 6.6L Duramax LB7, LLY or LBZ, including the 2007 Classic.
Specifications
- Construction: fabricated aluminum, laser cut, CNC bent and TIG welded, custom powder coated
- Cap: black anodized CNC machined billet aluminum, two-prong (clear anodized available separately)
- Sensor: serviceable thread-in low coolant level sensor
- Mounting: OEM location and mounting points
- Replaces GM part numbers: 15808714, 15290795, 19353729
- Shipping weight: 8.0 lbs
- Package dimensions: 16" W x 16" H x 10" L, ships in its own box
- Made in the USA
Key Features at a Glance
- Serviceable coolant level sensor - the OEM one is moulded in and cannot be replaced.
- Sight glass fitted from the factory - level check at a glance.
- Aluminum replaces yellowed plastic - and stays that way.
- Billet cap and overflow hose included - complete kit.
- OEM mounting points - bolt-in, basic hand tools.
- Custom powder coat finish - pick your color above.
Notes
- ⚠ Sensor orientation depends on which sensor you have. The current Gen 2 sensor (black body) must be installed with the arrow on the wire end pointing DOWN — if it points any other way the truck throws a low coolant light immediately. The older Gen 1 float sensor, now discontinued but still in circulation, is the opposite: its arrow must point UP. Check which one is in your kit before you tighten it.
- ⚠ Allow 24 hours after fitting the sensor before filling with coolant so the thread sealant cures.
- Lead time varies by color. WCFab Red, Candy Teal, Gloss White and Gloss Black are stocked and ship in 3-5 business days. All other colors are made to order on a 10-15 business day lead time.
- Running twin turbos? That build uses the twin turbo style tank (WCF100642) instead — it is smaller, mounts closer to the passenger fender and requires relocating the passenger battery. It is not a drop-in replacement for the OEM tank.
FASS SKU: WCFWCF100645
Manufacturer Part #: WCF100645
Questions? We’re Here to Help.
Have questions about upgrades for your 6.6L Duramax? Contact FASS Motorsports and we’ll get you dialed:
Phone: 636-429-7020
Email: info@fassmotorsports.com
This part fits the following vehicles:
| Years | Make & Model |
|---|---|
| 2001 | Chevrolet Silverado 2500 |
| 2001 | Chevrolet Silverado 3500 |
| 2001 | GMC Sierra 2500 |
| 2001 | GMC Sierra 3500 |
| 2007 | Chevrolet Silverado 2500 HD |
| 2007 | Chevrolet Silverado 3500 HD |
| 2007 | GMC Sierra 2500 HD |
| 2007 | GMC Sierra 3500 HD |
Fitment is listed by year, make and model. Some applications also depend on cab, bed, drivetrain or engine — if you are not sure, call 636-429-7020 or send us your vehicle details and we will confirm before you order.
